Method and apparatus for processing wafer-shaped articles

ABSTRACT

A device for processing wafer-shaped articles comprises a closed process chamber that provides a gas-tight enclosure. A rotary chuck is located within the closed process chamber. A heater is positioned relative to the chuck so as to heat a wafer shaped article held on the chuck from one side only and without contacting the wafer shaped article. The heater emits radiation having a maximum intensity in a wavelength range from 390 nm to 550 nm. At least one first liquid dispenser is positioned relative to the chuck so as to dispense a process liquid onto a side of a wafer shaped article that is opposite the side of the wafer-shaped article facing the heater.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to a method and apparatus for processingwafer-shaped articles, such as semiconductor wafers, in a closed processchamber.

2. Description of Related Art

Semiconductor wafers are subjected to various surface treatmentprocesses such as etching, cleaning, polishing and material deposition.To accommodate such processes, a single wafer may be supported inrelation to one or more treatment fluid nozzles by a chuck associatedwith a rotatable carrier, as is described for example in U.S. Pat. Nos.4,903,717 and 5,513,668.

Alternatively, a chuck in the form of a ring rotor adapted to support awafer may be located within a closed process chamber and driven withoutphysical contact through an active magnetic bearing, as is described forexample in International Publication No. WO 2007/101764 and U.S. Pat.No. 6,485,531. Treatment fluids which are driven outwardly from the edgeof a rotating wafer due to centrifugal action are delivered to a commondrain for disposal.

Although many methods and apparatus for single wafer wet processing areknown, it remains a difficult problem to strip photoresist fromsemiconductor wafers, especially when the photoresist is deeplyimplanted with ions such as boron and arsenic. Most such methods requirethe use of large volumes of concentrated sulfuric acid, which is arelatively expensive process chemical, and one that is moreoverimpractical to recycle.

SUMMARY OF THE INVENTION

The present inventors have developed improved methods and apparatus fortreatment of wafer-shaped articles in closed process chambers, based ontheir unexpected discovery that heating the wafer-shaped article in aparticular way, in combination with a controlled introduction of ozonegas into the chamber, results in a surprisingly effective removal ofeven deeply implanted photoresist from the wafer-shaped article.

Thus, in one aspect, the present invention relates to a device forprocessing wafer-shaped articles, comprising a closed process chambercomprising a housing providing a gas-tight enclosure. A rotary chuck islocated within the closed process chamber, and is adapted to hold awafer shaped article of a predetermined diameter thereon. A heater ispositioned relative to the chuck so as to heat a wafer shaped articleheld on the chuck from one side only and without contacting the wafershaped article. The heater emits radiation having a maximum intensity ina wavelength range from 390 nm to 550 nm. At least one first liquiddispenser is positioned relative to the chuck so as to dispense aprocess liquid onto a side of a wafer shaped article that is oppositethe side of the wafer shaped article facing the heater. The selectedwavelength enables primarily the substrate to be heated and not thechamber. Positioning the liquid dispenser on the opposite side of thewafer shaped article from the heater allows the front side of the wafershaped article to be treated as the wafer shaped article is heated fromthe back side.

In preferred embodiments of the device according to the presentinvention, the chuck is a magnetic ring rotor positioned inside thechamber, and surrounded by a stator positioned outside the chamber.

In preferred embodiments of the device according to the presentinvention, the chuck is driven by a motor whose output is transmitted toa rotary shaft connected to the chuck.

In preferred embodiments of the device according to the presentinvention, the chamber comprises an upper region in which an outlet ofthe at least one first liquid dispenser is located and a lower region inwhich or adjacent to which the heater is located, whereby the heater isconfigured to heat a wafer shaped article from an underside thereof andthe at least one first liquid dispenser is configured to dispenseprocess liquid onto an upper side thereof.

In preferred embodiments of the device according to the presentinvention, the heater emits radiation having a maximum intensity in awavelength range from 400 nm to 500 nm.

In preferred embodiments of the device according to the presentinvention, the heater comprises an array of blue light-emitting diodes.

In preferred embodiments of the device according to the presentinvention, the array of blue light-emitting diodes is substantiallycoextensive with a wafer shaped article of the predetermined diameter.

In preferred embodiments of the device according to the presentinvention, the device also includes an ozone generator configured todeliver ozone gas to a gas inlet that leads into the chamber.

In preferred embodiments of the device according to the presentinvention, the gas inlet is positioned relative to the chuck so as todeliver ozone gas toward a side of a wafer shaped article that isopposite the side of the wafer-shaped article facing the heater.

In preferred embodiments of the device according to the presentinvention, a first plate is positioned between the heater and a wafershaped article when held on the chuck, the first plate beingsubstantially transparent to radiation emitted by the heater.

In preferred embodiments of the device according to the presentinvention, the first plate is made of quartz or sapphire.

In preferred embodiments of the device according to the presentinvention, the first plate forms at least part of a wall of the chamber,the heater being mounted outside of the chamber.

In preferred embodiments of the device according to the presentinvention, the first plate is disposed above a base body of the chuckand below a wafer shaped article when held on the chuck, the first platebeing mounted on the chuck inside the chamber.

In preferred embodiments of the device according to the presentinvention, a second plate is mounted on the chuck for rotationtherewith, the second plate being on a same side of the wafer shapedarticle as the at least one first liquid dispenser, the second plateshielding an interior of one side of the chamber from liquid dropletsflung off of the wafer shaped article.

In preferred embodiments of the device according to the presentinvention, at least one second liquid dispenser is mounted on a sameside of the wafer shaped article as the heater.

In preferred embodiments of the device according to the presentinvention, the heater is configured to heat a silicon wafer of thepredetermined diameter to a temperature in excess of 300° C.

In another aspect, the present invention relates to a method forprocessing wafer-shaped articles, comprising positioning a wafer-shapedarticle of a predetermined diameter on a rotary chuck located within aclosed process chamber, heating the wafer shaped article from one sideonly and without contacting the wafer, with radiation having a maximumintensity in a wavelength range from 390 nm to 550 nm, and dispensingprocess liquid onto a side of the wafer shaped article that is oppositethe side of the wafer-shaped article facing the heater.

The heating may be performed simultaneously with the dispensing ofprocess liquid. Alternatively, or in addition, the dispensing of processliquid may be effected before and/or after heating of the wafer.

In preferred embodiments of the method according to the presentinvention, ozone that is primarily in gaseous form is introduced intothe closed process chamber. Preferably the ozone is introduced intocontact with the heated wafer shaped article after and/or during thetime that the wafer shaped article is heated with radiation having amaximum intensity in a wavelength range from 390 nm to 550 nm.

In preferred embodiments of the method according to the presentinvention, the introducing of ozone and the dispensing of process liquidare performed sequentially without intervening removal of the wafershaped article from the closed process chamber. This means that theliquid treatment can be conducted before and/or after the ozonetreatment.

In a preferred embodiment ozone gas is supplied to the surface of thewafer shaped article not facing the heater. This preferably is conductedby at least one nozzle directed toward the side of the wafer-shapedarticle not facing the heater. Alternatively, the ozone gas can besupplied into the chamber through any other orifice e.g. near the edgeof the wafer-shaped article of even through an opening in the heater.

In preferred embodiments of the method according to the presentinvention, the introducing of ozone and the dispensing of process liquidare performed simultaneously.

In preferred embodiments of the method according to the presentinvention, the wafer shaped article is a semiconductor wafer havingsemiconductor device components formed on a side of the wafer that isopposite the side facing the heater.

In preferred embodiments of the method according to the presentinvention, the process liquid is substantially free of sulphuric acid.

In preferred embodiments of the method according to the presentinvention, the heating of the wafer shaped article results in the wafershaped article attaining a temperature in excess of 300° C.

In yet another aspect, the present invention relates to a process forstripping photoresist from a substrate, comprising dispensing an aqueoushydrogen peroxide solution onto a surface of the substrate, wherein thesurface includes photoresist to be stripped, and wherein the substrateis disposed in a closed chamber; introducing an ozone atmosphere intothe closed chamber while the aqueous hydrogen peroxide solution resideson the surface of the substrate; heating the substrate; and removingstripped photoresist from the substrate.

In preferred embodiments of the process according to the presentinvention, the heating is performed at a temperature in the range of150° C. to 500° C.

In preferred embodiments of the process according to the presentinvention, the heating is performed at a temperature in the range of200° C. to 450° C.

In preferred embodiments of the process according to the presentinvention, the heating is performed at a temperature in the range of250° C. to 400° C., and preferably in excess of 300° C.

In preferred embodiments of the process according to the presentinvention, the aqueous hydrogen peroxide solution has a peroxideconcentration of 20-40%, preferably 25-35%, and more preferably 30-34%.

In preferred embodiments of the process according to the presentinvention, the substrate is a semiconductor wafer.

In preferred embodiments of the process according to the presentinvention, the semiconductor wafer is mounted on a spin chuck during theprocess.

In preferred embodiments of the process according to the presentinvention, introduction of the ozone atmosphere into the closed chambercommences prior to dispensing of the aqueous hydrogen peroxide solutiononto the surface of the substrate.

In preferred embodiments of the process according to the presentinvention, the dispensing is puddle dispensing, in which a predeterminedvolume of the aqueous hydrogen peroxide solution is maintained on thesurface of the substrate.

In preferred embodiments of the process according to the presentinvention, the dispensing is flow dispensing, in which the aqueoushydrogen peroxide solution is flowed across and off of the surface ofthe substrate.

In preferred embodiments of the process according to the presentinvention, the closed chamber is free of mineral acids during theprocess.

In preferred embodiments of the process according to the presentinvention, the closed chamber is free of sulfuric acid during theprocess.

In preferred embodiments of the process according to the presentinvention, the aqueous hydrogen peroxide solution is dispensed onto thesubstrate at a flow rate of 200-800 ml/min, preferably 300-700 ml/min,more preferably 400-600 ml/min, and most preferably 450-550 ml/min.

In preferred embodiments of the process according to the presentinvention, the aqueous hydrogen peroxide solution is maintained incontact with the substrate for 30-180 seconds, preferably 45-150seconds, more preferably 60-120 seconds and most preferably 80-110seconds.

In preferred embodiments of the process according to the presentinvention, the removing of stripped photoresist from the substratecomprises rinsing the substrate with deionized water.

In preferred embodiments of the process according to the presentinvention, the surface is contacted with nitrogen gas after theremoving, so as to dry the surface.

In preferred embodiments of the process according to the presentinvention, the photoresist to be stripped from the surface of thesubstrate is a carbon hardmask film.

In preferred embodiments of the process according to the presentinvention, the heating commences after introduction of ozone into theclosed chamber has commenced, and wherein the heating terminates whilethe aqueous hydrogen peroxide solution is still in contact with thesurface of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the invention will become moreapparent after reading the following detailed description of preferredembodiments of the invention, given with reference to the accompanyingdrawings, in which:

FIG. 1 is an explanatory cross-sectional side view of a process chamberaccording to a first embodiment of the invention, in its operatingposition;

FIG. 2 is an explanatory cross-sectional side view of a process chamberaccording to the first embodiment of the invention, in its loading andunloading position;

FIG. 3 is an enlarged view of the detail III in FIG. 1;

FIG. 4 is a view similar to that of FIG. 3, showing an alternativeembodiment;

FIG. 5 is an explanatory cross-sectional side view of a process chamberaccording to another embodiment of the invention;

FIG. 6 is an explanatory cross-sectional side view of a process chamberaccording to a still further embodiment of the invention;

FIG. 7 is an explanatory cross-sectional side view of a process chamberaccording to a yet still further embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to FIG. 1, an apparatus for treating surfaces ofwafer-shaped articles according to a first embodiment of the inventioncomprises an outer process chamber 1, which is preferably made ofaluminum coated with PFA (perfluoroalkoxy) resin. The chamber in thisembodiment has a main cylindrical wall 10, a lower part 12 and an upperpart 15. From upper part 15 there extends a narrower cylindrical wall34, which is closed by a lid 36.

A rotary chuck 30 is disposed in the upper part of chamber 1, andsurrounded by the cylindrical wall 34. Rotary chuck 30 rotatablysupports a wafer W during use of the apparatus. The rotary chuck 30incorporates a rotary drive comprising ring gear 38, which engages anddrives a plurality of eccentrically movable gripping members (not shown)for selectively contacting and releasing the peripheral edge of a waferW.

In this embodiment, the rotary chuck 30 is a ring rotor providedadjacent to the interior surface of the cylindrical wall 34. A stator 32is provided opposite the ring rotor adjacent the outer surface of thecylindrical wall 34. The rotor 30 and stator 34 serve as a motor bywhich the ring rotor 30 (and thereby a supported wafer W) may be rotatedthrough an active magnetic bearing. For example, the stator 34 cancomprise a plurality of electromagnetic coils or windings that may beactively controlled to rotatably drive the rotary chuck 30 throughcorresponding permanent magnets provided on the rotor. Axial and radialbearing of the rotary chuck 30 may be accomplished also by activecontrol of the stator or by permanent magnets. Thus, the rotary chuck 30may be levitated and rotatably driven free from mechanical contact.Alternatively, the rotor may be held by a passive bearing where themagnets of the rotor are held by correspondinghigh-temperature-superconducting magnets (HTS-magnets) that arecircumferentially arranged on an outer rotor outside the chamber. Withthis alternative embodiment each magnet of the ring rotor is pinned toits corresponding HTS-magnet of the outer rotor. Therefore the innerrotor makes the same movement as the outer rotor without beingphysically connected.

The lid 36 has a manifold 42 mounted on its exterior, which supplies amedium inlets 43, 44, 45 that traverse the lid 36 and open into thechamber above the wafer W. Preferably at least three nozzles provided.One of the nozzles 43, 44, 45 is supplied with ozone that is primarilyin gaseous form, from the ozone generator 41 indicated schematically inFIG. 1. The other two nozzles may for example supply an acid and arinsing liquid (such as deionized water or isopropyl alcohol),respectively.

It will be noted that the wafer W in this embodiment hangs downwardlyfrom the rotary chuck 30, supported by the gripping members of the chuck30, such that fluids supplied through inlets 43, 44, 45 would impingeupon the upwardly facing surface of the wafer W.

Another fluid inlet is shown schematically at 46, which in preferredembodiments communicates with a supply of nitrogen gas. If desired, aseries of such inlets may be provided at respectively different radialpositions along the lid 36.

In case wafer W is a semiconductor wafer, for example of 300 mm or 450mm diameter, the upwardly facing side of wafer W could be either thedevice side or the opposite side of the wafer W, which is determined byhow the wafer is positioned on the rotary chuck 30, which in turn isdictated by the particular process being performed within the chamber 1.

The apparatus of FIG. 1 further comprises an interior cover 2, which ismovable relative to the process chamber 1. Interior cover 2 is shown inFIG. 1 in its first, or closed, position, in which the rotary chuck 30is shielded from the outer cylindrical wall 10 of chamber 1. Cover 2 inthis embodiment is generally cup-shaped, comprising a base surrounded byan upstanding cylindrical wall 21. Cover 2 furthermore comprises ahollow shaft 22 supporting the base and traversing the lower wall 14 ofthe chamber 1.

Hollow shaft 22 is surrounded by a boss 12 formed in the main chamber 1,and these elements are connected via a dynamic seal that permits thehollow shaft 22 to be displaced relative to the boss 12 whilemaintaining a gas-tight seal with the chamber 1.

At the top of cylindrical wall 21 there is attached an annular deflectormember 24, which carries on its upwardly-facing surface a gasket 26 (seeFIG. 2). Cover 2 preferably comprises a fluid medium inlet 28 traversingthe base 20, so that process fluids and rinsing liquid may be introducedinto the chamber onto the downwardly facing surface of wafer W.

Cover 2 furthermore includes a process liquid discharge opening 23,which opens into a discharge pipe 25. Whereas pipe 25 is rigidly mountedto base 20 of cover 2, it traverses the bottom wall 14 of chamber 1 viaa dynamic seal 17 so that the pipe may slide axially relative to thebottom wall 14 while maintaining a gas-tight seal.

An exhaust opening 16 traverses the wall 10 of chamber 1, and isconnected to a suitable exhaust conduit (not shown).

The position depicted in FIG. 2 corresponds to loading or unloading of awafer W. In particular, a wafer W can be loaded onto the rotary chuck 30through the side door 50, which is shown in its open position in FIG. 2,so as to permit loading or unloading of a wafer W.

In FIG. 1, the interior cover 2 has been moved to its closed position,which corresponds to processing of a wafer W. That is, after a wafer Wis loaded onto rotary chuck 30, the door 50 is moved to its closed, orfirst, position as shown in FIG. 1, and the cover 2 is moved upwardlyrelative to chamber 1, by a suitable motor (not shown) acting upon thehollow shaft 22. The upward movement of the interior cover 2 continuesuntil the deflector member 24 comes into contact with the interiorsurface of the upper part 15 of chamber 1. In particular, the gasket 26carried by deflector 24 seals against the underside of upper part 15,whereas the gasket 18 carried by the upper part 15 seals against theupper surface of deflector 24.

When the interior cover 2 reaches its closed position as depicted inFIG. 1, there is thus created a second chamber 48 within the closedprocess chamber 1. Inner chamber 48 is moreover sealed in a gas tightmanner from the remainder of the chamber 1. Moreover, the chamber 48 ispreferably separately vented from the remainder of chamber 1.

During processing of a wafer, processing fluids may be directed throughmedium inlets 43-46 and/or 28 to a rotating wafer W in order to performvarious processes, such as etching, cleaning, rinsing, and any otherdesired surface treatment of the wafer undergoing processing.

The interior cover 2 in this embodiment is also provided with a heatingassembly 60, which is shown on an enlarged scale in FIG. 3. As shown inFIG. 3, the heating assembly 60 of this embodiment comprises amultiplicity of blue LED lamps 62 carried by the interior cover 2. Thecross-sectional view shows a line of such lamps, however, they arepreferably arranged so as to fill as fully as possible a circular areaon the interior cover 2 that is coextensive with the wafer W. The areaoccupied by the lamps 62 may if desired be somewhat larger than the areaof the wafer W that the chuck 30 is designed to hold.

This arrangement has the advantage that the wafer W can be heated by theheating assembly 60 over its full extent, from the center to theoutermost periphery of the wafer.

The array of blue LED lamps 62 in this embodiment is covered by a plate64. Plate 64 is preferably formed of quartz or sapphire, both of whichmaterials are substantially transparent to the wavelengths emitted bythe blue LED lamps 62. Other materials with similar transmissionproperties could thus be used for the plate 64. Plate 64 serves toprotect the LED lamps 62 from chemicals used in the process chamber. Acentral opening is formed in the interior cover 2 and the plate 64, toaccommodate the fluid medium inlet 28.

A second plate 54 is positioned above the wafer W in this embodiment.Whereas plate 64 is stationary with the interior cover 2, plate 54 ismounted on the rotary chuck and therefore rotates therewith. If desired,plate 54 could also be mounted in a stationary manner relative to chuck30, but it is preferred to have the plate 54 rotate with chuck 30.

Plate 54 preferably overlies the entire upper surface of wafer W, exceptthat plate 54 preferably has a central opening 55 through which pass thedischarge ends of the fluid inlets 43, 44, 45.

Provision of the plate 54 integrated with chuck 30, between wafer W andthe top 36 of chamber 1, gives rise to a number of advantages. The plate54 in use is rotating with the chuck and at the same speed thereof, andhence also is rotating with a wafer W gripped by the chuck 30, and alsoat the same speed as wafer 30. This design therefore serves to minimizeturbulence in the employed process fluids.

Furthermore, it is possible to minimize temperature differences during adrying process by cooling the plate 54 with deionized water. Stillfurther, residual process media above the wafer W on the underside ofplate 54, caused for example by splashing and/or condensation, can berinsed simultaneously during the aforementioned deionized water rinse,or can be rinsed with deionized water after completion of the process.

As the plate 54 segregates the chamber interior from the upwardly facingside of the wafer W, this serves to minimize contamination bybacksplashing and or particles. Plate 54 furthermore permits enhancedatmosphere control above the wafer. Still further, this design alsoallows gap processes, i.e., processes in which the gap between wafer andthe chuck is filled with liquid.

The blue LED lamps 62 have a maximum intensity at a wavelength of about450 nm. Other sources of radiation could be used, but it is preferred touse sources emitting radiation having a maximum intensity in awavelength range from 390 nm to 550 nm and more preferably in awavelength range from 400 nm to 500 nm.

Whereas radiation of that wavelength characteristic is largelytransmitted by the plate 64, that same radiation is largely absorbed bythe semiconductor material of the wafer W, especially when the wafer Wis silicon. It has been found to be especially advantageous to heat thewafer W from one side in this manner, while exposing the opposite sideof wafer W to ozone gas within the process chamber.

More particularly, a silicon wafer W having device structures formedthereon, and from which a layer of deeply implanted photoresist isformed, is positioned on chuck with the device side facing up. Becausethe wafer W is heated from below by the blue LED lamps 62, and becausethe radiation from those lamps is largely absorbed by the wafer,photo-corrosion of the device side of the wafer W is prevented.

In the other hand, this manner of heating the wafer W providessufficient energy to activate the ozone that has been supplied to thedevice side of the wafer. This technique is in contrast to IR heating,which heats the wafer and surrounding device structure indiscriminately.

Because the present device and methods selectively heat the wafer,cooling performance is also enhanced. For example, as the plate 64largely transmits the radiation emitted from lamps 62, the plate 64 doesnot heat up nearly so much as with IR heating, and therefore can help tomore rapidly dissipate the heat from the wafer W after a heating stageis completed.

Although in the present embodiment the LED lamps 62 are beneath thewafer and the ozone inlet is above, it will be appreciated that theirpositions could be reversed.

In FIG. 4, a variation of the heating assembly 60 is shown, in which theplate 64 forms with the interior cover 2 a sealed chamber through whicha cooling fluid 66 (e.g. gas or liquid) is circulated, so as to preventoverheating of the LED lamps 62.

FIG. 5 shows another embodiment of a device for treatment ofwafer-shaped articles W according to a preferred embodiment of theinvention. The device of FIG. 5 differs from that of FIGS. 1 and 2 inthat the plate 54 of the preceding embodiment is not present in theembodiment of FIG. 5. Without the plate 54 present, the gripping pins 40are visible, which project downwardly from the chuck 30 and engage theperipheral edge of the wafer.

FIG. 6 shows yet another embodiment of a device for treatment ofwafer-shaped articles W according to a preferred embodiment of theinvention. The device comprises a spin chuck 102 and a surroundingcollector 103 positioned in a closed process chamber 101. The collector103 comprises a bottom plate 105, an annular duct 108, an outerside-wall 113, an annular top cover 112, a baffle 114 and a splash guard107. The collector 103 is connected to the spin chuck 102 via a liftingmechanism (not shown) concentric to the axis of rotation of the spinchuck 102.

The edge of the bottom plate 105 is tightly connected with the innerupwardly projecting cylindrical sidewall of the annular duct 108. Theouter diameter of the plate 105 is at least as big as the diameter ofthe wafer W. The peripheral edge of the annular duct 108 is tightlyconnected with the bottom edge of the cylindrical outer side-wall 113.The top edge of the cylindrical side-wall 113 is tightly connected withthe peripheral edge of an annular top cover 112. The diameter of inneredge of the top cover is about 2 mm greater than the diameter of thespin chuck 102 so that the spin chuck 102 can easily pass through theopening of the top cover 112.

Within the collector 103 an annular splash guard 107 is horizontallyarranged. The splash guard 107 is tapered towards its periphery and itsinner edge is about 2 mm greater than the diameter of the spin chuck 102so that the spin chuck 102 can easily pass through the opening. Theperipheral edge of the splash guard 107 is tightly connected with theouter side-wall 113. The splash-guard 107 is arranged between the topcover 112 and the duct 108.

On the gas-entry side of the collector 103 a baffle 114 is tightlyconnected with the cover 112 on the baffle's upper edge and with thesplash-guard 107 on the baffle's lower side. The baffle has the shape ofa section of a cylinder.

A device of this type is more fully described in commonly-owned U.S.Pat. No. 8,147,618.

Different media (liquid and/or gas) can be supplied to the wafer-shapedarticle W through a first media supply 118 located near the centre ofthe plate and directed towards the disc-like article. A second mediasupply 120 is provided in the spin chuck near the centre of the spinchuck and directed towards. Therefore a disc-like article (e.g. asemiconductor wafer) can be treated from both sides eithersimultaneously or alternatively.

The bottom plate 105 in this embodiment is provided with an array ofblue LED lamps 162 as described in connection with the foregoingembodiments, which lamps 162 are covered with a plate 164 of sapphire orquartz, as also described previously. Thus, when chuck 102 is lowered soas to place wafer W in close proximity to the lamps 162, heating of thewafer W can be effected as described in connection with the foregoingembodiments. Before, during or after such heating, gas such as ozone gascan be introduced to the upper side of wafer W through inlet 120, as thewafer W is rotated by a motor driven shaft in the direction of therotary arrow shown in FIG. 6.

FIG. 7 shows still another embodiment of a device for treatment ofwafer-shaped articles W according to a preferred embodiment of theinvention. The device comprises a spin chuck 210, which is mounted tothe rotor of a hollow-shaft motor 240, and a stationary nozzle head 220which penetrates through a central hole of the spin chuck 210. Thestator of the hollow-shaft motor 240 is mounted to the mounting plate242. Nozzle head 220 and mounting plate 242 are mounted to the samestationary frame 244, within a closed process chamber 201.

The spin chuck 210 comprises six cylindrically shaped holding elements214 with eccentrically mounted gripping pins, only three of which arevisible in FIG. 7. The gripping pins are rotated about the axis of theirrespective holding element by a ring gear 216, so as to secure andrelease a wafer W.

The non-rotating nozzle head 220 penetrates through the center hole ofthe spin chuck leaving a gap between the spin chuck and the nozzle headof 0.2 mm. The gap can be purged by gas (e.g. nitrogen) duringprocessing. In this embodiment, three pipes 224, 228, 229 lead throughthe nozzle head. Pipes 224, 228, 229 are each connected to different gasor liquid sources, as described in connection with the inlets 43, 44, 45of the first embodiment, and project 5 mm below the bottom surface ofthe spin chuck as well as the nozzle head.

The openings (nozzles) of pipes 224, 228, 229 are directed towards theupwardly facing surface of the wafer. Another nozzle assembly 258 isprovided below the spin chuck in order to supply liquid and/or gas tothe downwardly-facing surface of the wafer W.

Nozzle 258 passes through a central opening formed in a heater assembly260. Heater assembly 260 comprises an array of blue LED lamps 262, whichare covered by a plate 264 made of sapphire or quartz, as in thepreceding embodiments. No plate is provided above the wafer W in thisembodiment; however, it will be appreciate that such a plate could beprovided, in which case it would preferably be mounted centrally to thenozzle head 220 and extend radially outwardly therefrom in a cantileverfashion to a diameter that is just inside the inside edges of theholding elements 214.

The present inventors have surprisingly discovered that a dry processutilizing ozone that is primarily in gaseous form, together with heatingas described above, more effectively removes deeply implantedphotoresist than conventional wet methods.

Furthermore, the dry process with ozone gas can be alternated with a wetprocess in which the wafer is treated for example with SC1 (aqueoussolution of ammonium hydroxide and hydrogen peroxide) before and/orafter the dry process, without removing the wafer W from the processchamber between the wet and dry processes. Such a sequential techniqueeven more fully removes deeply implanted photoresist, yet does notrequire the use of sulphuric acid as in conventional wet strippingtechniques.

The following table sets forth exemplary processing conditions for usein preferred embodiments of the methods and apparatus according to thepresent invention.

Baseline recipe Dry O3 + Wet 2. 1 2 3 5 6 7 9 O3 pre Temp HT 4 DIW DIWWet 2 8 N2 Parameter purge ramp up process cool down (cool down) (+chuckclean) (i.e. SC1) DIW dry Current step time (sec) 40 24 60 60 10 60 6060 70 [Range] [10-40] — [30-120] [10-60] [10-30] [10-60] [10-90] [20-60][20-70] chuck speed (rpm) 10/400 10/400 10/400 400 800 400 400 400 900O3 gas 280 280 280 — — — — — — Chuck clean — — — — Y/N Y — Y/N — mediumtop center flow — — — — N Y Y Y — medium bottom center fow — — — — Y Y YY — Heating YIn the table, O3 denotes ozone that is primarily in gaseous form. Itwill be understood that in practice ozone is delivered together with acarrier gas, preferably oxygen, because ozone generators transform ozoneto oxygen only partially. HT in the table stands for high temperatureand DIW means deionized water.

Another process that can be performed using the devices of the foregoingembodiments is a perozone technique for stripping photoresist, andpreferably encrusted or deeply implanted photoresist, in which hydrogenperoxide is dispensed onto a wafer surface in the closed processchamber, either by puddle dispensing or by flow dispensing. Ozone thatis primarily in gaseous form is introduced into the closed processchamber while an aqueous solution of hydrogen peroxide is present on thewafer surface.

The ozone and hydrogen peroxide are supplied to the same side of thewafer, e.g., an upwardly facing side carrying semiconductor devicestructures that are at least partly manufactured. The wafer is heatedfrom the opposite side using the heater assembly as described above.Heating can occur before, during and/or after introduction of theaqueous hydrogen peroxide and ozone gas into the process chamber.

The heating is performed until the wafer reaches a temperature in therange of 150° C. to 500° C., preferably 200° C. to 450° C., morepreferably 250° C. to 400° C., and most preferably in excess of 300° C.The aqueous hydrogen peroxide solution has a peroxide concentration of20-40%, preferably 25-35%, and more preferably 30-34%.

Introduction of the ozone atmosphere into the closed chamber maycommence prior to or subsequent to dispensing of the aqueous hydrogenperoxide solution onto the surface of the substrate. Heating of thewafer may commence before or after introduction of ozone into the closedchamber has commenced. Heating of the wafer preferably is terminatedterminates while the aqueous hydrogen peroxide solution is still incontact with the surface of the substrate. Preferably, the process doesnot use mineral acids, especially sulphuric acid.

The aqueous hydrogen peroxide solution may be dispensed onto the waferat a flow rate of 200-800 ml/min, preferably 300-700 ml/min, morepreferably 400-600 ml/min, and most preferably 450-550 ml/min. Theaqueous hydrogen peroxide solution is maintained in contact with thesubstrate for 30-180 seconds, preferably 45-150 seconds, more preferably60-120 seconds and most preferably 80-110 seconds.

The process may also include rinsing the wafer with deionized water, anddrying with nitrogen gas.

While the present invention has been described in connection withvarious preferred embodiments thereof, it is to be understood that thoseembodiments are provided merely to illustrate the invention, and thatthe invention is not limited to those embodiments, but rather includesthat which is encompassed by the true scope and spirit of the appendedclaims.

What is claimed is:
 1. A device for processing a wafer, the devicecomprising: a process chamber providing a gas-tight enclosure; a rotarychuck located within the process chamber and above the wafer, whereinthe rotary chuck comprises a first plate, wherein the first plate islocated above the wafer and rotates with the rotary chuck, wherein therotary chuck is adapted to hold the wafer, and wherein the first plateis cooled via a first cooling fluid; a heater positioned relative to therotary chuck and facing an underside of the wafer, wherein the heater isconfigured to heat the underside of the wafer, wherein the heater emitsradiation having a maximum intensity in a wavelength range between390-550 nanometers, wherein the rotary chuck holds the wafer between thefirst plate and the heater, wherein the heater heats the underside ofthe wafer, wherein no heater is disposed on an upper side of the wafer,and wherein the upper side opposes the underside; and a first liquiddispenser positioned relative to the chuck and configured to dispense aprocess liquid onto the upper side of the wafer, wherein the upper sideis opposite the underside of the wafer, wherein the process chambercomprises an upper region above the wafer in which an outlet of thefirst liquid dispenser is located and a lower region below the wafer inwhich the heater is located, and the heater is non-rotatably mountedwithin the process chamber.
 2. The device according to claim 1, whereinthe rotary chuck comprises a magnetic ring rotor positioned inside theprocess chamber and surrounded by a stator positioned outside theprocess chamber.
 3. The device according to claim 1, wherein: the rotarychuck is driven by a motor; and an output of the motor is transmitted toa rotary shaft connected to the rotary chuck.
 4. The device according toclaim 1, wherein the heater emits radiation having a maximum intensityin a wavelength range between 400-500 nanometers.
 5. The deviceaccording to claim 1, wherein the heater comprises an array of bluelight-emitting diodes.
 6. The device according to claim 5, wherein thearray of blue light-emitting diodes occupies an area that is coextensivewith or larger than an area occupied by the wafer.
 7. The device ofclaim 5, wherein the blue light-emitting diodes occupy an area largerthan an area occupied by the wafer.
 8. The device according to claim 1,further comprising an ozone generator configured to deliver an ozone gasto a gas inlet of the process chamber.
 9. The device according to claim8, wherein: the gas inlet is positioned relative to the rotary chuck anddelivers the ozone gas toward the upper side of the wafer during adrying process; and the heater is configured to heat the wafer toactivate the ozone gas in the process chamber.
 10. The device accordingto claim 9, wherein the heater heats the wafer until the wafer isgreater than or equal to 300° C.
 11. The device of claim 9, wherein thefirst liquid dispenser and the gas inlet operates in alternating manner,such that a wet process and the drying process are alternately performedwhile the heater heats the wafer to remove photoresist from the waferwithout use of sulfuric acid.
 12. The device of claim 11, wherein theprocess liquid includes ammonium hydroxide or hydrogen peroxide.
 13. Thedevice of claim 9, wherein, while the heater is heating the wafer, thegas inlet delivers the ozone gas to the upper side of the wafer when theprocess liquid is present on the upper side of the wafer.
 14. The deviceaccording to claim 1, further comprising a second plate disposed betweenthe heater and the wafer when the wafer is held by the rotary chuck,wherein the second plate is transparent to radiation emitted by theheater.
 15. The device according to claim 14, wherein the second plateis made of quartz or sapphire.
 16. The device according to claim 14,wherein the second plate is disposed below a body of the rotary chuckand below the wafer when the wafer is held by the rotary chuck.
 17. Thedevice according to claim 1, wherein: the first plate is on a same sideof the wafer as the first liquid dispenser; and the first plate shieldsan interior of one side of the process chamber from liquid dropletsflung off of the wafer.
 18. The device according to claim 1, furthercomprising a second liquid dispenser located below the wafer and on asame side of the wafer as the heater.
 19. The device according to claim1, wherein the heater is configured to heat the wafer to a temperaturein excess of 300° C.
 20. The device of claim 1, wherein the firstcooling fluid comprises deionized water and is supplied during a dryingprocess to rinse off an underside of the first plate.
 21. The device ofclaim 1, further comprising a second plate disposed between the heaterand the wafer, wherein the second plate is transparent to wavelengths ofemitted radiation of the heater.
 22. The device of claim 21, wherein thesecond plate is formed of quartz or sapphire.
 23. The device of claim21, wherein: the heater comprises an array of light-emitting diodes; asecond cooling fluid is circulated around the light-emitting diodes toprevent the light-emitting diodes from overheating; the heater isdisposed on a cover and between the cover and the second plate; and thecooling fluid is provided in a space between the second plate and thecover.
 24. The device of claim 23, wherein the light-emitting diodes aredisposed across the wafer between a center of the wafer and an outermostperiphery of the wafer to heat a whole surface area of the underside ofthe wafer.
 25. The device of claim 1, wherein the heater heats theunderside of the wafer while the process liquid is dispensed on theupper side of the wafer.
 26. A device for processing a wafer, the devicecomprising: a process chamber providing a gas-tight enclosure; a rotarychuck located within the process chamber and above the wafer, whereinthe rotary chuck comprises a first plate, wherein the first plate islocated above the wafer and rotates with the rotary chuck, wherein therotary chuck is adapted to hold the wafer, and wherein the first plateis cooled via a first cooling fluid; a heater positioned relative to therotary chuck and facing an underside of the wafer, wherein the heater isconfigured to heat the underside of the wafer, wherein the heater emitsradiation having a maximum intensity in a wavelength range between390-550 nanometers; a second plate disposed between the heater and therotary chuck, wherein the rotary chuck holds the wafer between the firstplate and the second plate; a first liquid dispenser positioned relativeto the chuck and configured to dispense a process liquid onto an upperside of the wafer, wherein the upper side is opposite the underside ofthe wafer, wherein the process chamber comprises an upper region abovethe wafer in which an outlet of the first liquid dispenser is locatedand a lower region below the wafer in which the heater is located, andthe heater is non-rotatably mounted within the process chamber; and asecond liquid dispenser disposed in the lower region and dispensing asecond cooling fluid between the heater and the second plate.
 27. Thedevice of claim 26, wherein: the heater comprises an array oflight-emitting diodes; the second cooling fluid is circulated around thelight-emitting diodes to prevent the light-emitting diodes fromoverheating; the heater is disposed on a cover and between the cover andthe second plate; and the cooling fluid is provided in a space betweenthe second plate and the cover.
 28. A device for processing a wafer, thedevice comprising: a process chamber providing a gas-tight enclosure; arotary chuck located within the process chamber and above the wafer,wherein the rotary chuck comprises a first plate, wherein the firstplate is located above the wafer and rotates with the rotary chuck,wherein the rotary chuck is adapted to hold the wafer, and wherein thefirst plate is cooled via a first cooling fluid; a heater positionedrelative to the rotary chuck and facing an underside of the wafer,wherein the heater is configured to heat the underside of the wafer,wherein the heater emits radiation having a maximum intensity in awavelength range between 390-550 nanometers, wherein the heatercomprises an array of light-emitting diodes, and wherein the rotarychuck holds the wafer between the first plate and the heater; a firstliquid dispenser positioned relative to the chuck and configured todispense a process liquid onto an upper side of the wafer, wherein theupper side is opposite the underside of the wafer, wherein the processchamber comprises an upper region above the wafer in which an outlet ofthe first liquid dispenser is located and a lower region below the waferin which the heater is located, and the heater is non-rotatably mountedwithin the process chamber; and a second dispenser disposed in the lowerregion and dispensing a second cooling fluid, wherein the second coolingfluid is circulated around the light-emitting diodes to prevent thelight-emitting diodes from overheating.
 29. The device of claim 28,wherein the second cooling fluid contacts the light emitting diodes.